How can I make a specific part of particles a different color?
You can use Vertex Pain method. Create the material with the color you want, then where you select object/edit mode find vertex paint. Then just pain over the parts of object you want with that color.  Or you can select faces and add that color to them. This tutorial describes the technique: https://www.youtube.com/watch?v=0lj643VmTsg&amp;t=448s

Edit: I am allso new so take it with a grain of sand :)